<template>
  <!-- 商品分类导航 -->
  <div class="type-nav">
    <div class="container">
      <div @mouseleave="leaveShow" @mouseenter="enterShow">
        <h2 class="all">全部商品分类</h2>
<!--        过度动画 要于v-show配合使用-->
        <transition name="sort">
          <div class="sort"
               v-show="show">
            <div class="all-sort-list2" @click="goSearch">
              <div v-for="(c1,index) in categoryList"  :key="c1.categoryId" class="item" :class="{cur:currentIndex==index}">
                <h3 @mouseenter="changeIndex(index)">
                  <a :data-categoryName="c1.categoryName" :data-category1Id="c1.categoryId" >{{c1.categoryName}}</a>
                </h3>
                <div class="item-list clearfix" :style="{display:currentIndex==index?'block':'none'}">
                  <div class="subitem" v-for="c2 in c1.categoryChild"  :key="c2.categoryId">
                    <dl class="fore">
                      <dt>
                        <a :data-categoryName="c2.categoryName" :data-category2Id="c2.categoryId">{{c2.categoryName}}</a>
                      </dt>
                      <dd>
                        <em v-for="c3 in c2.categoryChild"  :key="c3.categoryId">
                          <a :data-categoryName="c3.categoryName" :data-category3Id="c3.categoryId">{{c3.categoryName}}</a>
                        </em>
                      </dd>
                    </dl>
                  </div>
                </div>
              </div>
            </div>
          </div>
        </transition>
      </div>
      <nav class="nav">
        <a href="###">服装城</a>
        <a href="###">美妆馆</a>
        <a href="###">柯基超市</a>
        <a href="###">全球购</a>
        <a href="###">闪购</a>
        <a href="###">团购</a>
        <a href="###">1元专区</a>
        <a href="###">秒杀</a>
      </nav>
    </div>
  </div>
</template>

<script>
import {mapState} from 'vuex'
import throttle from 'lodash/throttle'
export default {
  name: "TypeNav",
  data(){
    return{
     //存储用户鼠标移动
      currentIndex:-1,
      show:true
    }
  },
  methods:{
    //鼠标进入一级分类,一级联动节流
    changeIndex:throttle(function (index){
      //index鼠标移上一级分类的索引值
      this.currentIndex=index
    },50),
    //鼠标移除一级分类
    leaveShow(){
      this.currentIndex=-1
      //如果页面不在home页，进行鼠标移除隐藏商品分类组件
      if (this.$route.path!='/home'){
        this.show=false
      }
    },
    goSearch(event){
      let element = event.target
      let {categoryname,category1id,category2id,category3id} = element.dataset
      if (categoryname){
        //整理路由跳转的参数
        let loction = {name:'search'}
        let query = {categoryName:categoryname}
       if (category1id){
         query.category1Id=category1id
       }else if (category2id){
         query.category2Id=category2id
       }else{
         query.category3Id=category3id
       }
       //判断是否有params参数
        if (this.$route.params){
          loction.params=this.$route.params
          //整理完参数
          loction.query=query
          //路由跳转
          this.$router.push(loction)
        }
      }
    },
    //当鼠标移入的时候，商品分类列表进行展示
    enterShow(){
      this.show=true
    }
  },
  mounted() {

    //挂载完毕，show的值变为false,如果不是home组件，将三级联动隐藏
    if (this.$route.path!='/home'){
      this.show=false
    }
  },
  computed:{
    ...mapState({
      categoryList:(state => {
         return state.home.categoryList
      })
    })
  }
}
</script>

<style scoped lang="less">
.type-nav {
  border-bottom: 2px solid #e1251b;

  .container {
    width: 1200px;
    margin: 0 auto;
    display: flex;
    position: relative;

    .all {
      width: 210px;
      height: 45px;
      background-color: #e1251b;
      line-height: 45px;
      text-align: center;
      color: #fff;
      font-size: 14px;
      font-weight: bold;
    }

    .nav {
      a {
        height: 45px;
        margin: 0 22px;
        line-height: 45px;
        font-size: 16px;
        color: #333;
      }
    }

    .sort {
      position: absolute;
      left: 0;
      top: 45px;
      width: 210px;
      height: 461px;
      position: absolute;
      background: #fafafa;
      z-index: 999;

      .all-sort-list2 {
        .cur{
          background: skyblue;
        }
        .item {
          h3 {
            line-height: 30px;
            font-size: 14px;
            font-weight: 400;
            overflow: hidden;
            padding: 0 20px;
            margin: 0;

            a {
              color: #333;
            }
          }
          .item-list {
            display: none;
            position: absolute;
            width: 734px;
            min-height: 460px;
            background: #f7f7f7;
            left: 210px;
            border: 1px solid #ddd;
            top: 0;
            z-index: 9999 !important;

            .subitem {
              float: left;
              width: 650px;
              padding: 0 4px 0 8px;

              dl {
                border-top: 1px solid #eee;
                padding: 6px 0;
                overflow: hidden;
                zoom: 1;

                &.fore {
                  border-top: 0;
                }

                dt {
                  float: left;
                  width: 54px;
                  line-height: 22px;
                  text-align: right;
                  padding: 3px 6px 0 0;
                  font-weight: 700;
                }

                dd {
                  float: left;
                  width: 415px;
                  padding: 3px 0 0;
                  overflow: hidden;

                  em {
                    float: left;
                    height: 14px;
                    line-height: 14px;
                    padding: 0 8px;
                    margin-top: 5px;
                    border-left: 1px solid #ccc;
                  }
                }
              }
            }
          }
        }
      }
    }
  //  过渡动画的样式
    //进入的开始状态
    .sort-enter{
      height: 0px;
    }
    //进入的结束状态
    .sort-enter-to{
      height: 461px;
    }
    //定义的时间
    .sort-enter-active{
      transition: all .5s linear;
    }
  }
}
</style>